In most marine platforms, particularly those used in offshore work, the structure is subjected to weather conditions which prevail in the area. These structures are constructed to rest on the ocean floor, and are of sufficient durability to maintain a work platform or deck a desired distance above the water's surface.
Since structures of this type are fully exposed to the weather, they must be built and protected to resist damage that might occur as a result of inclement weather such as storms or even hurricane conditions. In the instance of the latter, the combined action of wind and waves can be devastating unless exposed parts of the structure are either protected or sufficiently reinforced to resist the condition.
Although the marine structures here contemplated are fabricated of steel columns and members, the more fragile segments of the platform can sustain damage due to severe contact by wind and high waves.
In the instance of the platform's stairway which extends from the deck downward to the water's surface, the stair structure, by its nature is relatively fragile and susceptible to damage. Even in those instances where the stairway can be elevated to be beyond the reach of damaging waves, the structure is none the less exposed to high winds which can cause twisting and distortion.
Toward overcoming this susceptible feature in a marine structure, as hereinafter disclosed, the structure's access stairway which extends between the platform's deck and its landing stage, is fabricated such that the stairway is laterally braced against forceful lateral displacement. Such displacement could result from contact between the stairway and driven water or high winds.
The stairway is articulated to the extent of being pivotally engaged at its upper end to the marine structure. The stairway lower end, however, can be elevated to a position such that the entire unit will be in a raised condition.
Reinforcement of the raised lower end is assured by registering said lower end in a docking structure which depends from the platform's deck section.
It is, therefore, an object of the invention to provide an offshore structure's access stairway which is capable of withstanding severe and adverse weather conditions at an offshore site.
A further object is to provide a marine structure in which the access stairway between the elevated working deck and the water level, can be adjusted to a raised, braced position which puts it beyond reach of waves and the like.